I am somehow not able to correct my mailaddress. I subscribed here a long time ago with an old mailaddress (that does not exist anymore).In the user control panel I have to type my password to do this and the system refuses the one I am using to log in.

Well, that's unfortunate. Could you please write a short bugreport about that? Please pay attention to no include any personal details like mail adress there, as you can't remove stuff from bugreports See https://wiki.mageia.org/en/How_to_report_a_bug_properly and for completeness's sake and also to allow others to follow up on that bug report, please also post the link to it here in the thread, thanks.

And in parallel you can send me the old and new mail adress for comparison, I can try to change them via the admin panel.Otherwise you would need to wait for the resolution of the bugreport, and that might take a _really_ long time :/